1. Field of the Invention
The invention relates to a vibration frame for the print elements of a matrix-line printer, which print elements are constructed according to the clapper armature construction. Component units, neighboring in line direction, are furnished at a profile rod. Said component units include, in each case, a magnetic yoke, an electromagnetic coil, a clapper armature, a clapper-armature pivoting hinge support, a restoring spring, and a print element attached at the clapper armature.
2. Brief Description of the Background of the Invention Including Prior Art
Such matrix line printers serve mainly for printing out of a high data output generated by an electronic computer, and such matrix line printers are consequently coordinated to a computer, where the volume of data corresponds to that of a mini-computer or, respectively, of a main frame computer.
In contrast to serial printers, matrix line printers generate dot lines in line direction, where a series of horizontal dot lines are necessary for the formation of a complete character line or of a section of a picture. Therefore, conventionally only one dot print element is disposed in the advance direction of the recording material for several character columns. According to a conventional matrix line printer, such as Mannesmann Tally MT 660/MT 690, there are provided 66 or, respectively, 132 print elements. Such a matrix line printer prints between 600 and 900 lines per minute in high-speed mode and about 280 to 450 lines in letter-quality mode.
The initially mentioned vibration frame for the print elements of a matrix line printer is known from the European Patent Publication No. 0,098,316.
The conventional construction provides that the electromagnets are formed as clapper armature magnets and that the vibration frame comprises a profile rod, extending in the line direction, where the larger, open cross-sectional part of the profile rod faces the print roller. The cross-sectional part is formed by three sides of a rectangle including wall sections. One wall section of the rectangular cross-sectional part continues at its free end, facing the print roller side, in a smaller cross-sectional part of the profile rod. Said smaller cross-sectional part of the profile rod is delimited by three sides of a rectangle forming wall sections and includes an open side. The open side of the smaller cross-sectional part is neighboring to the open side of the larger cross-sectional part and runs with its open plane perpendicular to the open side of the larger cross-sectional part. The magnetic yoke and the electromagnetic coil are disposed in the larger cross-sectional part and the clapper armature at the open side while, in each case, a short print pin, the clapper armature tip, extending through the open side of this cross-sectional part, and a set screw for the clapper armature, are received in the smaller cross-sectional part. Based on this construction, however, the clapper armature is not positioned in a defined manner and the danger exists that a lateral motion interferes with the mode of operation of the clapper armature, such that the desired high frequency of the clapper armature construction cannot be achieved.